# characteristics.description[].text
Protocols: Human cell lines (MCF-7) were cultured in DMEM (D6546-500ML; Sigma Aldrich) each supplemented with 10% fetal bovine serum (F7524-500ML; Sigma Aldrich), 2 mM L-glutamine (G7513- 100ML; Sigma Aldrich), 50 units/ml of penicillin, and 50 μg/ml of streptomycin (P0781-100ML; Sigma Aldrich). 0.5% oxygen for 16 hours total RNA was prepared using mirVanaTM miRNA isolation kit (AM1560; Life Technologies), according to manufacturer’s protocol. Genomic DNA was removed from RNA samples using TURBO DNA-freeTM Kit (AM1907; Life Technologies) according to the manufacturer’s protocol. poly-A selection from total RNA